Running ISPconfig and additional Apache on Port 80?

So if I have multiple IP addresses such as 1.1.1.1 and 2.2.2.2 for example, can I run ISPconfig on port 80 of one IP address and my main apache on port 80 of the other address without any conflict and what configuration would be required of each?

Sorry if this is a repeat, but I couldn't easily understand the previous ones if they were trying to do this exact thing or not.